Differential scanning calorimetry (DSC), and other techniques as needed, will be applied to study of the thermodynamics and other characteristics of conformational changes in proteins, nucleic acids and nucleoproteins. DSC will also be employed in the study of the thermotropic behavior membranes and related model systems. Isothermal calorimetry and equilibrium measurements will be employed to evaluate the thermodynamic parameters, with emphasis on the heat capacity changes, of macromolecular interactions, including: protein-ligand interactions; the interactions involved in ribosome assembly; the assembly of tobacco mosaic virus and other viruses. Work will be continued on the thermodynamics of transfer of model substances and groups from non-polar to aqueous environment, in connection with our efforts to gain further insight into the importance of hydrophobic and hydropholic interactions in the structure of biopolymers. BIBLIOGRAPHICAL REFERENCES: Heats of Binding Proteins to Globular Proteins. D.D.F. Shiao and J.M. Sturtevant, Biopolymers 15, 1201 (1976). A Beta-Coupled Gauche Kink Description of the Lipid Bilayer Phase Transition. M. Jackson, Biochemistry 15, 2555, (1976).